Molecular Evolution of Antigen-Processing Genes in Salamanders: Do They Coevolve withMHCClass I Genes?
Genome Biology and Evolution, vol. 13
Abstract
Proteins encoded by antigen-processing genes (APGs) prepare antigens for presentation by the major histocompatibility complex class I (MHC I) molecules. Coevolution between APGs and MHC I genes has been proposed as the ancestral gnathostome condition. The hypothesis predicts a single highly expressed MHC I gene and tight linkage between APGs and MHC I. In addition, APGs should evolve under positive selection, a consequence of the adaptive evolution in MHC I. The presence of multiple highly expressed MHC I genes in some teleosts, birds, and urodeles appears incompatible with the coevolution hypothesis. Here, we use urodele amphibians to test two key expectations derived from the coevolution hypothesis: 1) the linkage between APGs and MHC I was studied in Lissotriton newts and 2) the evidence for adaptive evolution in APGs was assessed using 42 urodele species comprising 21 genera from seven families. We demonstrated that five APGs (PSMB8, PSMB9, TAP1, TAP2, and TAPBP) are tightly linked (<0.5 cM) to MHC I. Although all APGs showed some codons under episodic positive selection, we did not find a pervasive signal of positive selection expected under the coevolution hypothesis. Gene duplications, putative gene losses, and divergent allelic lineages detected in some APGs demonstrate considerable evolutionary dynamics of APGs in salamanders. Overall, our results indicate that if coevolution between APGs and MHC I occurred in urodeles, it would be more complex than envisaged in the original formulation of the hypothesis.
Authors 12
-
Gemma Palomar corresponding
Affiliation as printed
Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Kraków, Poland
-
Affiliation as printed
Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Kraków, Poland
-
Leiden University · Naturalis Biodiversity Center
Affiliation as printed
Institute of Biology Leiden, Leiden University, The Netherlands
Naturalis Biodiversity Center, Leiden, The Netherlands
-
Affiliation as printed
Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut, USA
-
Affiliation as printed
Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
-
Affiliation as printed
Naturalis Biodiversity Center, Leiden, The Netherlands
-
Centre National de la Recherche Scientifique · University of Milan · Laboratoire d'Écologie Alpine · Université Savoie Mont Blanc · Université Grenoble Alpes
Affiliation as printed
Department of Environmental Sciences and Policy, University of Milano, Italy
Laboratoire d’Ecologie Alpine (LECA), CNRS, Université Grenoble Alpes and Université Savoie Mont Blanc, Grenoble, France
-
Affiliation as printed
Department of Advanced Genomic and Laboratory Medicine, Graduate School of Medicine, University of the Ryukyus, Nishihara-cho, Japan
-
Oklahoma State University · Seoul National University
Affiliation as printed
Department of Integrative Biology, Oklahoma State University, Stillwater, Oklahoma, USA
School of Biological Sciences, Seoul National University, South Korea
-
Affiliation as printed
Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
-
Affiliation as printed
Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Kraków, Poland
-
Wiesław Babik corresponding
Affiliation as printed
Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Kraków, Poland
Cited by 10 stored of 10
10 results
No patents citing this paper on Lens.org (checked 2026-10-11).